According to the 2012-13 guidelines released by the Centers for Disease Control and Prevention (CDC):

Everyone 6 months of age and older should get a yearly flu vaccine.

The flu vaccine is approved for use in people older than 6 months, including healthy people and people with chronic medical conditions.

People should get their seasonal flu vaccine as soon as vaccine becomes available in their community. Early vaccination allows the vaccine's protective antibodies to be in place when flu activity is high.

Flu Tips from the CDC

The CDC also offers the following tips to help you and your family get through this year's flu season:

Most influenza occurs from October through May. Getting vaccinated as soon as you can is the best strategy for prevention.

Adults and older children need one dose of influenza vaccine each year. Some children 9 years old and younger need two doses. If you have questions about proper dosage for your child, talk to your primary care doctor.

Certain people should not get the flu vaccine. People who occupy the following categories should talk to their doctor before getting the flu vaccine:

People who have had severe allergies, including a severe allergy to eggs. A severe allergy to any vaccine component may be a reason not to get the vaccine.

People who have ever had Guillain-Barré Syndrome (a severe paralytic illness, also called GBS).

People who are moderately or severely ill. If you are ill, talk to your doctor about whether to reschedule the vaccination. People with a mild illness can usually get the vaccine.